WASHINGTON -- In striking ways, this is America's deepest worry: an Islamic nation in the world's most unstable region, home to al-Qaida's global headquarters, engaged in a shooting war with insurgents and radical terrorists, now beset with escalating political turmoil - and at the center of it all, an arsenal of nuclear bombs.
Pakistan's growing turbulence is raising fears that al-Qaida and allied Islamist extremist groups, which have had deep roots inside Pakistan's intelligence services, will renew their determination to acquire a nuclear device, or that control of Pakistan's prized nuclear arsenal could be seized as a bargaining tool by a political faction or be used as a threat in a conflict inside Pakistan or in the region.
"We will watch it quite closely," Army Lt. Gen. Carter F. Ham, director of operations for the Joint Chiefs of Staff, said yesterday. "Any time a nation that has nuclear weapons experiences a situation such as Pakistan is at present, that is a primary concern," he told reporters at the Pentagon, "and that's probably all I can say about that."
"This is a bad one," agreed Robert S. Norris, a nuclear weapons expert at the Natural Resources Defense Council.
Pakistan was thrown into a state of emergency Saturday when the president and military chief, Gen. Pervez Musharraf, suspended the constitution, shut down independent news media and arrested thousands as violent demonstrations erupted across the country.
Pakistan's estimated arsenal of between 45 and 60 nuclear weapons is controlled by a 10-man National Command Authority (NCA) headed by Musharraf, said Pakistani Brig. Gen. Naeem Salik, who retired two years ago as a senior officer within the NCA.
Pakistan's warheads "are kept under tight security. They are more than adequately guarded," Salik said in an interview yesterday. He said there is "a standard two-man rule" to authenticate access to nuclear release codes, a standard that is "universally" used by all nuclear weapons powers.
Salik, currently a visiting scholar at the Johns Hopkins University's School of Advanced International Studies, scoffed at the idea that the political crisis threatened the security of the nuclear arsenal. "A firecracker goes off, and the media starts jumping all over us," he said. "By the same analogy, when 9/11 happened, one could have asked what would become of America's nuclear weapons."
The United States counts Pakistan as a close ally in what President Bush terms "the global war on terror" and has provided $10.58 billion in mostly military aid. Even so, U.S. officials seemed unclear about the outcome of the current crisis.
A senior White House official, asked this week if it is "just a matter of time" until Musharraf is violently deposed, said: "You don't really know until it happens."
The White House declined yesterday to comment on Pakistan's nuclear weapons.
Military experts said U.S. options to intervene, if Pakistan's nuclear weapons are threatened or go missing, are limited. Any armed intervention would be met by stiff opposition from Pakistan's powerful military forces, said Dakota Wood, a retired Marine officer who is a senior analyst at the independent Center for Strategic and Budgetary Assessments in Washington.
By any measure, Pakistan is under considerable strain. Aside from the political crisis, Pakistani military units recently have suffered humiliating defeats in the Northwest Frontier Province against Taliban and al-Qaida forces, raising questions about morale within the armed forces under Musharraf's direction. Suicide bombings sweeping Pakistan in recent months have killed more than 600, according to the Pakistani government.
Since he seized control of Pakistan in 1999, Musharraf has survived at least four assassination attempts by Islamist radicals, most recently a week ago when a suicide bomber killed seven people in a blast near Musharraf's headquarters in Rawalpindi.
Amid this turmoil, U.S. officials and private analysts acknowledged that little is known about the security of Pakistan's nuclear arsenal, begun when Pakistan tested a nuclear device in 1998.
Pakistan's National Command Authority, which controls the arsenal, consists of the president and prime minister, the civilian heads of major ministries, the chairman of the joint chiefs of staff and other senior military officers. "They sit in times of crisis, they have the codes with them," Salik said. "It is a clear-cut and defined line of authority."
Pakistan's nuclear stockpile is thought to consist mostly of aircraft bombs fitted for U.S.-supplied F-16 fighter bombers, though Pakistan has recently tested the Shaheen-II missile, which can carry a warhead about 1,500 miles. In addition, Pakistan operates at least one nuclear reactor producing weapons-grade plutonium and is building a second plutonium reactor at a site in the Punjab, surrounded by six antiaircraft missile batteries, according to the Natural Resources Defense Council, an environmental action organization that tracks U.S. and foreign nuclear weapons and facilities.
The nuclear warheads are separated or "de-mated" from the missiles or bomb casings that would carry them in an attack, said Hans Kristensen of the Federation of American Scientists, and might be stored in bunkers or a tunnel at the Sargodha air base and weapons complex west of Lahore near the Indian border.
Nuclear weapons security at these sites has been beefed up considerably in the past five years, spurred by revelations that from the 1980s through 2003, Pakistan's senior nuclear scientist, A.Q. Khan, and some of his top associates had provided nuclear weapons designs and material to North Korea, Libya and Iran.
Each Pakistani warhead is fitted with a permissive action link (PAL), a code-lock device that prevents unauthorized release of the weapon, Salik said. Pakistan has also set up a personnel reliability system of the type used by the United States to continually monitor the financial status, marital condition, mental health and other aspects of officials in the nuclear system to ensure they are not disloyal or vulnerable to bribery or blackmail. Also, Pakistan has a 10,000-member security force for its nuclear facilities, commanded by a two-star general.
Many safety issues have been discussed at joint U.S.-Pakistani conferences in the United States in recent years, including one in April sponsored by the nonprofit Partnership for Global Security, a Washington organization dedicated to improving nuclear security.
"The United States has been engaged with Pakistan on the question of nuclear security," said Kenneth N. Luongo, director of the organization. "It's not been widely publicized. The Pakistanis themselves have become quite serious about trying to provide assurances to the rest of the world that they're on the ball, and I think they've made some progress."
But Salik stressed that Pakistan has not accepted U.S. technical advice on PALs or any other aspect of its nuclear program. "We have developed our own systems," he said. "The problem is that people won't grant that we can produce PALs even if we can produce our own nuclear weapons."